Field of the Invention
The present invention, in general, is directed to a mesh patch for surgical procedures and, more particularly, to a cover for such mesh patches and methods of performing surgeries with such mesh patches.
Description of Related Art
The groin is one of the natural weak areas in the abdominal wall and is the most common site for abdominal herniation. In particular, inguinal hernias are defined as those occurring above the abdominocrural crease. Inguinal hernias are usually classified as direct or indirect. The sac of an indirect inguinal hernia passes obliquely or indirectly toward and ultimately into the scrotum. The sac of a direct inguinal hernia protrudes directly outward and forward. Clinically distinguishing an indirect from a direct inguinal hernia is often impossible and is of little importance since the operation to repair them is substantially the same.
Traditionally, inguinal hernias have been repaired via one of two types of operative procedure. A first technique is a laparoscopic approach which requires the patient to be under a general anesthetic. However, this approach is less preferred because it has a high early recurrence rate and a steep learning curve for the surgeon. A more preferred approach is called an “open technique” in which a small two (2) to three (3) inch incision is made in the inguinal area after the patient is under local, regional, or general anesthesia and the hernia is repaired.
In order to enhance the “open technique”, surgically implantable mesh patches for the repair of inguinal and other abdominal wall hernias have been provided. Tension free surgical repairs of hernias have been developed using-synthetic mesh materials to bridge and to patch hernia defects. Repairs utilizing such surgically implantable mesh patches resulted in both a decrease in the recurrence rate as well as a decrease in the amount of a patient's post operative discomfort. Patients undergoing these more advanced procedures were able and are able to resume their normal activities sooner.
With reference to FIGS. 1 through 3, an example of such a mesh patch, denoted generally as reference numeral 1, is the Paritex ProGrip™ Mesh manufactured by Covidien AG, 150 Glover Avenue, Norwalk, Conn. 06856. Mesh patch 1 has, viewed from above, the general shape of an ellipse. This ellipse includes a lower edge 3a and an upper edge 3b with a large radius of curvature and two lateral edges 3c, 3d with a small radius of curvature. The shape of upper edge 3b is specifically adapted to the anterior inguinal region and more precisely to the space formed after opening of the aponeurosis of the external oblique muscle, access to the conjoined tendon and the aponeurosis of the rectus muscle, the latter being fixed between the insertion of the aponeurosis of the external oblique muscle and that of the rectus muscle. This anatomical asymmetry combined with the presence of a flap 5 means mesh patch 1 can provide either a right reinforcement or a left reinforcement. Mesh patch 1 shown in FIG. 1 is a right reinforcement (relative to the patient). The large curvature of lower edge 3a allows a perfect match to the crural arch as far as the pubis.
Mesh patch 1 also includes a slit 7 positioned perpendicular to upper edge 3b and extending substantially over half of the width of mesh patch 1. The inner end of slit 7 opens into an orifice 9 which is cylindrical and which, for example, has a diameter of 3 to 7 millimeters. Flap 5 has a shape of a sector of a circular annulus and is connected via one of its radial edges to one of the edges of mesh patch 1 which delimits the slit 7. Flap 5 is joined to mesh patch 1 in such a way that the concavity of its inner and outer arched edges is directed towards orifice 9.
Mesh patch 1 is made of a sheet of low-weight monofilament polyester knitted fabric 11 having a top surface 13 and a bottom surface 15. The polyester knitted fabric 11 has a low weight isoelastic structure with large pores as shown in FIG. 2. In addition, polyester knitted fabric 11 incorporates resorbable polylactic acid (PLA) micro-hooks 17 on bottom surface 15 thereof. Resorbable PLA micro-hooks 17 provide self-gripping properties to mesh patch 1 during a procedure and the first month post-implantation. Mesh patch 1 is configured to be secured around a spermatic cord of the patient using flap 5. Flap 5 is made of the same fabric as mesh patch 1 (i.e., polyester with polylactic acid micro-hooks knitted fabric), thereby providing it with self-gripping properties. After complete tissue ingrowth and complete resorption of PLA micro-hooks 17, mesh patch 1 ensures long term abdominal wall reinforcement.
However, the implantation of such a patch can be challenging. More particularly, during implantation using the recommended procedure, PLA micro-hooks 17 of mesh patch 1 can stick to tissue surrounding the implantation site and may need to be removed from such tissue. As mesh patch 1 is removed, the fragile PLA micro-hooks can be torn from bottom surface 15 of mesh patch 1. Accordingly, once mesh patch 1 arrives at the desired location, most, if not all, of the PLA micro-hooks 17 may be disengaged from bottom surface 15 of mesh patch 1, and the surgeon may be required to stitch mesh patch 1 in position. In addition, if flap 5 is positioned too loose or tight around the patient's spermatic cord various problems can arise. For instance, positioning flap 5 too tightly around the spermatic cord can lead to testicular ischemia whereas positioning flap 5 too loosely around the spermatic cord can lead to a recurrent hernia.
Accordingly, a need exists for a removable cover for mesh patch 1 that prevents PLA micro-hooks 17 from securing themselves to surrounding tissue during implantation of mesh patch 1. In addition, a need exists for a surgical method of implanting mesh patch 1 using such a cover.